What is a hybrid heat pump?

A hybrid heat pump combines an ASHP with a gas boiler. The system automatically switches between the two based on outdoor temperature and energy costs. Above the balance point temperature, the heat pump runs (more efficient). Below the balance point, the boiler takes over (higher capacity at low temperatures).

What is the balance point temperature?

The balance point is the outdoor temperature at which it becomes more cost-effective to switch from the heat pump to the gas boiler. This depends on the electricity-to-gas price ratio and the heat pump COP at that temperature. Typically 0-5C in the UK at current tariffs.

How much does a hybrid system save compared to gas only?

A hybrid system typically saves 15-30% on heating bills compared to a gas boiler alone, depending on the balance point setting and energy prices. The heat pump handles 60-80% of annual heating hours (mostly in milder weather), where it is most efficient.

Is a hybrid system cheaper than a full heat pump?

A hybrid system has lower installation costs (smaller HP, no radiator upgrades needed) and can be cheaper to run when gas is relatively cheap compared to electricity. However, a well-designed full heat pump system with appropriate radiators can achieve lower long-term costs and greater carbon savings.

Do I need to upgrade radiators for a hybrid system?

Usually not. The beauty of a hybrid system is that the gas boiler handles the coldest days when radiator output would be most compromised. The heat pump runs mainly in milder weather when existing radiators can cope. This avoids the radiator upgrade cost of a full heat pump system.

TradeCalculator

Hybrid Heat Pump Calculator

Calculate the balance point temperature for a hybrid heat pump system. See how hours split between HP and gas boiler, and compare annual costs.

Annual Heat Demand

Total annual heating energy

Balance Point Temperature

HP switches to boiler below this

Electricity Price

Gas Price

How We Calculate This

This calculator analyses a hybrid heat pump system by splitting annual heating hours between the heat pump and gas boiler based on the balance point temperature.

How the split works

Above balance point: Heat pump runs (typically 60-80% of heating hours)
Below balance point: Gas boiler runs (typically 20-40% of hours)
Energy split: HP handles most energy as milder hours are more numerous
Optimisation: Balance point can be adjusted based on tariff changes

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.